#include <iostream>
using namespace std;
/*
    c++ union:
    - 大小为最大成员的大小
    - 
 */

union one4all {
    int int_val;
    unsigned int unint32_val;
    long long_val;
    double double_val;
};


int main() {
    one4all pail;
    pail.int_val = 0x80000000;
    cout << pail.int_val << endl;
    cout << pail.unint32_val << endl;
    return 0;
}